The effect of emotional support on maternal oxytocin levels in labouring women.

OBJECTIVE: The presence of a supportive companion to women in labour has been found to reduce the duration of labour and the incidence of oxytocin augmentation. The mechanism which produces this improvement is unknown but work in animals suggests that environmental disturbance produces changes in endogenous oxytocin secretion. This study was carried out to assess maternal oxytocin secretion in relation to the presence of a supportive companion in labour. STUDY DESIGN: A randomised controlled trial involving allocation of unsupported women in the first stage of labour to a period of 1 h with a supportive companion or 1 h without. Sixteen women with uncomplicated singleton pregnancies who were in the active phase of the first stage of labour were studied. Maternal oxytocin levels were assayed by radioimmunoassay for 16 min (eight specimens) before and after the support or control period. RESULTS: There are no differences between maternal oxytocin levels in the two groups of patients. There was no difference in either of the two groups between the oxytocin levels pre and post the support/control period. CONCLUSIONS: One hour of birth support in the first stage of labour did not improve maternal oxytocin levels when compared to a control group.

Treatment outcome of women with a single ovary undergoing in vitro fertilisation cycles.

INTRODUCTION: Women with a single ovary present a unique problem in assisted reproductive techniques. The aim of our study was to compare the ovarian response and pregnancy rates of women with one ovary and those with two ovaries in assisted reproduction. METHODS: A total of 18 consecutive women with a single ovary (n is 22 cycles) were identified. The control group included 44 women with two ovaries and mechanical infertility, who were selected as frequency-matched samples (2:1) to meet the distribution of age at treatment and race in the single ovary group. All patients underwent controlled ovarian hyperstimulation treatment via the long down-regulation protocol using a gonadotropin-releasing hormone agonist. Standard procedures were carried out for gamete-embryo handling, and embryo transfer was performed using a soft catheter on day two in all cases. The luteal phase was supported by progesterone or Pregnyl after oocyte pick-up. RESULTS: The duration of stimulation (11.3 +/- 1.7 versus 10.1 +/- 1.4 days) and the total follicle stimulating hormone (FSH) consumption (3906.8 +/- 1860.6 mIU/ml versus 2900.0 +/- 1440.0 mIU/ml) were significantly higher, and the mean number of oocytes (10.8 +/- 4.5 versus 16.8 +/- 10.9) and metaphase II oocytes collected (9.5 +/- 4.5 versus 13.3 +/- 7.7) were significantly lower in the single ovary group (p is less than 0.05). The clinical pregnancy rates (31.8 percent versus 43.2 percent) were comparable between the two groups. CONCLUSION: Although women with a single ovary required significantly higher doses of FSH and a longer duration of stimulation, as well as produced less oocytes, their clinical pregnancy rates were comparable to those of women with two ovaries in assisted reproduction.

Gastrointestinal neurotensin-like immunoreactivity (NTLI) in lean and obese Zucker rats.

Neurotensin-like immunoreactivity (NTLI) was measured in gastric antral, pancreatic and jejuno-ileal extracts of lean and obese Zucker rats. No significant difference was found in pancreatic or antral NTLI levels, but significantly diminished levels of NTLI were found in jejuno-ileal extracts of the obese rats.

Serum CA 125 concentrations in women with endometriosis or uterine fibroids treated with gonadotrophin-releasing hormone agonist analogues.

We assessed the possible role of CA 125 in the monitoring of gonadotrophin-releasing hormone (GnRH) agonist analogue therapy in women with endometriosis and uterine fibroids. Serum concentrations of this cell surface antigen did not correlate with uterine volume and appeared to have no value in the assessment of shrinkage of uterine fibroids during GnRH agonist treatment. While CA 125 levels were not always elevated in subjects with endometriosis, they fell during treatment in all patients. The change accurately reflected therapeutic progress in these women and was of particular value in those patients who had commenced therapy with elevated levels. It is suggested that CA 125 may be useful in the monitoring of therapeutic progress in selected patients with endometriosis treated with GnRH agonists; the need for surgical follow-up may be obviated.

Previous cesarean section and abortion as risk factors for developing placenta previa.

OBJECTIVE: To determine the risk of subsequent occurrence of placenta previa in women with a history of previous cesarean sections and/or spontaneous and induced abortions. METHODS: A retrospective analysis of all single gestation deliveries at National University Hospital of Singapore from 1993-1997 was done. Women with placenta previa were identified by clinical or ultrasonographic diagnosis. RESULTS: Of the 16,169 singleton deliveries, 164 women (1.0%) had placenta previa. Women with placenta previa had a significantly higher incidence of previous cesarean sections (p < 0.001). Among the 164 women with placenta previa, women with 1, 2, and 3 previous cesarean sections had 2.2 (95% CI 1.4, 3.4), 4.1 (95% CI 1.9, 8.8) and 22.4 (95% CI 6.4, 78.3) times increased risk of developing placenta previa respectively. Similarly, women with 2 or more previous abortions had a 2.1 (95% CI 1.2, 3.5) times increased risk of subsequently developing placenta previa. CONCLUSION: There is a strong association between previous cesarean section and risk of subsequent development of placenta previa. This risk increased with the number of previous cesarean sections. Increasing frequency of abortions was also found to predispose a woman to placenta previa.

Effects of morphine administration on the fetal production of oxytocin in labour.

1. Animal and human work has indicated that maternal oxytocin secretion is under the control of endogenous opiates. Previous workers have described the fetal production of oxytocin in addition to maternal production. The study of the interaction between exogenously administered opiates and oxytocin secretion may give insight into the activity of any opiate-mediated regulatory mechanism of oxytocin secretion in the fetus. This study was designed to investigate the effect of an opiate (5 mg of morphine) given to the mother on the fetal production of oxytocin in labour. 2. Morphine was given by the attending clinicians for analgesic purposes to women in the first stage of labour. After delivery umbilical artery vein and maternal vein specimens were taken. 3. Four groups of patients were studied: women after normal vaginal delivery without analgesia in labour (n=10); women after normal vaginal delivery who had morphine administration in the first stage of labour (n=12); women who had an emergency Caesarean section in the first stage of labour (n=11); women who had an elective Caesarean section at term who were not in labour (n=11). 4. Oxytocin levels were measured by radioimmunoassay in the maternal vein, umbilical artery and umbilical vein specimens. Morphine was measured by radioimmunoassay in the umbilical vein specimens. 5. The umbilical artery minus vein concentration of oxytocin was calculated for each patient (A-V). There was no change in the umbilical (A-V) concentration of oxytocin if morphine had been given to the mother in labour; this applied to fetuses delivered vaginally or by Caesarean section. When the fetuses who were exposed to morphine were analysed separately, there was no correlation between the umbilical vein morphine concentration and the umbilical (A-V) oxytocin concentration either in Caesarean or vaginal deliveries. 6. Fetal oxytocin production was not affected by the maternal administration of morphine in the first stage of labour. This applies to the oxytocin production in the first and second stage of labour.

The effect of morphine and naloxone administration on maternal oxytocin concentration in late pregnancy.

OBJECTIVE: Modification of the inhibitory control of oxytocin secretion by endogenous opiates in late pregnancy may be one of the factors involved in the onset of labour. The interrelationships between exogenously administered opioids and oxytocin may demonstrate activity of this control mechanism. This study was undertaken to investigate the effect of an opiate and an opiate antagonist on maternal oxytocin levels in late pregnancy. DESIGN: Patients were randomized to receive either morphine (5 mg), naloxone (2.4 mg) or sterile water (1 ml) intravenously. PATIENTS: Thirty women with singleton pregnancies greater than 36 weeks gestation who were not in labour were studied. MEASUREMENTS: Blood for peripheral oxytocin levels was sampled every 2.5 minutes for 15 minutes before and 15 minutes after administration of the assigned substance. Oxytoxin was measured by radioimmunoassay. Peripheral beta-endorphin levels were measured at the beginning and end of the study. RESULTS: There was no significant change in the maternal oxytocin concentration after administration of either morphine, naloxone or sterile water compared to pretreatment levels. beta-Endorphin levels did not change significantly, either from the beginning to the end of the study, or between groups. CONCLUSION: In late pregnancy exogenous opiates and opiate antagonists have no effect on maternal peripheral oxytocin levels.

The effect of morphine and naloxone administration on plasma oxytocin concentrations in the first stage of labour.

OBJECTIVE: We investigated the effect of an opiate (morphine) and an opiate antagonist (naloxone) on the maternal secretion of oxytocin in the first stage of labour. DESIGN: Patients were randomized to receive either morphine 5 mg (n = 9), naloxone 1.2 mg (n = 10) or sterile water (n = 9) which was injected intravenously. PATIENTS: Healthy women in the first stage of labour between 3 and 6 cm dilated with no prior analgesia or oxytocin administration were recruited for the study. MEASUREMENTS: Peripheral maternal oxytocin levels were measured by radioimmunoassay for 15 minutes before and 15 minutes after administration of the assigned substance. Sampling was at 2.5 minute intervals. RESULTS: Significant reduction in the mean oxytocin concentration was found in the patients who received morphine (-2.62 pmol/l/sample) but no change was found in the naloxone group (+0.57 pmol/l/sample) when compared with controls (+0.64 pmol/l/sample). CONCLUSION: Maternal oxytocin secretion is inhibited by exogenous opiates in the first stage of labour while an effect of opiate antagonism was not demonstrated.

The 24-hour rhythm of oxytocin and beta-endorphin secretion in human pregnancy.

OBJECTIVE: Animal work suggests that maternal oxytocin secretion is influenced by the secretion of endogenous opioids in pregnancy. Spontaneous labour and pre-labour uterine activity follow a 24-hour rhythm the origin of which has not been explained but may be related to diurnal changes in oxytocin secretion. This study was performed to document the changes over a 24-hour period in maternal oxytocin and beta-endorphin secretion. DESIGN: A 4-hourly blood profile was undertaken for a 24-hour period. PATIENTS: Sixteen women with singleton pregnancies of more than 36 weeks gestation and 10 women with pregnancies in the mid trimester were studied. MEASUREMENTS: Blood was sampled 4-hourly for 24 hours beginning at 1200 h. Oxytocin was measured in all patients and beta-endorphin-like immunoreactivity was measured in 15 patients. RESULTS: A simple index was defined for comparing night-time levels to daytime levels for both oxytocin and beta-endorphin. In all cases more than 36 weeks gestation the index was positive for oxytocin (night-time levels were higher) and in all cases the index was negative for beta-endorphin (night-time levels were lower). In the mid trimester women all values of the index for oxytocin were positive but in the beta-endorphin group equal numbers demonstrated a positive or a negative index. CONCLUSIONS: Reciprocal 24-hour rhythms were demonstrated between oxytocin and beta-endorphin; however, it is not clear whether this relationship is causal.

Morphine suppresses the oxytocin response in breast-feeding women.

The activity of opiate-mediated regulatory mechanisms of oxytocin secretion during breast-feeding was studied by the administration of either morphine, naloxone or placebo to women prior to the commencement of breast-feeding. Seventeen healthy women in the first week after delivery who had established lactation were randomized to receive either intravenous morphine 5 mg (n = 6), naloxone 2.4 mg (n = 6) or a placebo, sterile water (n = 5), which was given prior to commencement of breast-feeding. Oxytocin levels were measured by radioimmunoassay prior to initiation of breast-feeding and then at 2-min intervals until the feed was complete. Breast-feeding produced a significant rise in oxytocin levels in the control and naloxone groups but no significant rise in the patients given morphine. There was a significant reduction in oxytocin response following morphine administration when compared to placebo but not between naloxone and placebo. In conclusion, oxytocin secretion to breast-feeding is inhibited by exogenous morphine when compared to a control group but the administration of naloxone did not produce a significant difference from control.

Ghrelin is released from rat hypothalamic explants and stimulates corticotrophin-releasing hormone and arginine-vasopressin.

Ghrelin and synthetic growth hormone secretagogues have diverse effects on the hypothalamus including effects on appetite and the growth hormone axis as well as on the hypothalamus-pituitary-adrenal (HPA) axis. We previously studied the effect of synthetic growth hormone secretagogues on CRH and AVP release from rat hypothalami in vitro, and now report on the effects of ghrelin on CRH and AVP release. The ghrelin protein content and ghrelin output from rat hypothalamic explants was measured using a specific novel ghrelin enzyme immunoassay. The effect of 10(-8) M to 10(-6) M ghrelin on CRH and AVP release was studied in the rat hypothalamic explants, where stimulation with des-octanoyl ghrelin was used as control. The presence of both ghrelin mRNA and protein could be shown in the rat hypothalamus. Ghrelin output was detected in the incubation fluid of rat hypothalamic explants and could be stimulated with high potassium concentrations. Our data also demonstrated a dose-dependent effect of ghrelin on both CRH and AVP release, while des-octanoylated ghrelin showed no effect on either peptide. In summary, the current data suggest that ghrelin is expressed in the hypothalamus both at RNA and the protein levels. Ghrelin stimulates the HPA axis in the rat via stimulation of both CRH, and particularly, AVP release from the hypothalamus. The local autocrine/paracrine and endocrine effects of ghrelin in the hypothalamus could influence all the hormonal systems involved in ghrelin effects, including growth hormone release, the HPA axis and appetite.